package dd.lo.chapter10;

import dd.lo.util.ImageUtils;
import javafx.application.Application;
import javafx.application.Platform;
import javafx.concurrent.Task;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.FlowPane;
import javafx.stage.FileChooser;
import javafx.stage.Stage;
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.MatOfByte;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.util.ArrayList;
import java.util.List;

/**
 * 代码样例基于Example 10-1. Using cv::threshold() to sum three channels of an image
 */
public class Example1 extends Application {

    private static final int DEFAULT_WIDTH = 1080;
    private static final int DEFAULT_HEIGHT = 768;

    public static final double ONE_THIRD = 1.0 / 3.0;

    public static void main(String[] args) {
        System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
        launch(args);
    }

    private ImageView imageView;

    @Override
    public void start(Stage stage) {
        Button imageChooser = new Button("选择图片");
        imageChooser.setOnMouseClicked(e -> {
            FileChooser fileChooser = new FileChooser();
            fileChooser.setTitle("请选择图片");
            fileChooser.setInitialDirectory(new File(System.getProperty("user.home") + "/Downloads")
            );
            fileChooser.getExtensionFilters().addAll(
//                    new FileChooser.ExtensionFilter("All Images", "*.*"),
                    new FileChooser.ExtensionFilter("JPEG", "*.jpeg"),
                    new FileChooser.ExtensionFilter("WEBP", "*.webp"),
                    new FileChooser.ExtensionFilter("PNG", "*.png"),
                    new FileChooser.ExtensionFilter("JPG", "*.jpg"),
                    new FileChooser.ExtensionFilter("GIF", "*.gif"),
                    new FileChooser.ExtensionFilter("BMP", "*.bmp")
            );
            File imgFile = fileChooser.showOpenDialog(stage);
            if (null == imgFile) {
                System.out.println("用户取消选中文件");
                return;
            }
            //读取一张图片
            Mat srcImg = Imgcodecs.imread(imgFile.getAbsolutePath(), Imgcodecs.IMREAD_UNCHANGED);
            if (srcImg.empty()) {
                throw new RuntimeException("图片读取失败");
            }
            thresholdTruncate(srcImg);
        });
        FlowPane bottomControl = new FlowPane();
        bottomControl.getChildren().addAll(imageChooser);
        bottomControl.setPrefHeight(50);
        BorderPane root = new BorderPane();
        imageView = new ImageView();
        root.setCenter(imageView);
        root.setBottom(bottomControl);
        Scene scene = new Scene(root, DEFAULT_WIDTH, DEFAULT_HEIGHT + 50);
        stage.setScene(scene);
        stage.setTitle("Example1-Sum channels and threshold truncate");
        stage.setResizable(false);
        stage.show();
    }

    private void thresholdTruncate(Mat srcImg) {
        Task<Void> task = new Task<Void>() {
            @Override
            protected Void call() {
                Mat dst = new Mat();
                //Split image onto the color planes.
                List<Mat> planes = new ArrayList<>(3);
                Core.split(srcImg, planes);
                Mat b = planes.get(0), g = planes.get(1), r = planes.get(2), s = new Mat();
                //Add equally weighted rgb values.
                Core.addWeighted(r, ONE_THIRD, g, ONE_THIRD, 0.0, s);
                Core.addWeighted(s, 1.0, b, ONE_THIRD, 0.0, s);
                //Truncate values above 100.
                Imgproc.threshold(s, dst, 100, 100, Imgproc.THRESH_TRUNC);
                //调整图片大小以用于展示
                ImageUtils.fitImgSize(dst, DEFAULT_WIDTH, DEFAULT_HEIGHT);
                MatOfByte buffer = new MatOfByte();
                Imgcodecs.imencode(".jpeg", dst, buffer);
                Platform.runLater(() -> imageView.setImage(new Image(new ByteArrayInputStream(buffer.toArray()))));
                return null;
            }
        };
        new Thread(task).start();
    }
}
